Page 358 - ARM 64 Bit Assembly Language

348 Chapter 10

10.5.2.2 Operations

Name Effect Description
vorr Vd[] ← Vd[] ∨ (uimm8 shif t) Logical OR
vbic Vd[] ← Vd[] ∧ (uimm8 shif t) Bit Clear

10.5.2.3 Examples

1 bic v0.2s, #0xFF // clear least significant bytes
2 // of v0.s[0] and v0.s[1]
3 orr v3.8h, #0x80,lsl #8 // set sign bit of every halfword
4 // in v3

10.6 Basic arithmetic instructions

Advanced SIMD provides many instructions for addition, subtraction, and multiplication, but
does not provide an integer divide instruction. When division cannot be avoided, it is per-
formed by multiplying the reciprocal, as was described in Chapter 7 and Chapter 8.When
dividing by a constant, the reciprocal can be calculated in advance. For dividing by variables,
Advanced SIMD provides instructions for quickly calculating the reciprocals of the elements
in a vector. In most cases, this is faster than using a divide instruction. For floating point num-
bers, the FP/NEON divide instructions can be used.

10.6.1 Vector add and subtract

The add and fadd instructions add corresponding elements in two vectors and store the re-
sults in the corresponding elements of the destination register. The sub and fsub instructions
subtract elements in one vector from corresponding elements in another vector and store the
results in the corresponding elements of the destination register. Other versions of the add and
subtract instructions allow mismatched operand and destination sizes, and the saturating ver-
sions prevent overflow by limiting the range of the results. The following instructions perform
vector addition and subtraction:

add Vector integer add,
fadd Vector floating point add,
qadd Vector saturating add,
addl Vector add long,